Dr. Bob, help please
posted by josh on .
does the density of an element have anything to do with the number of elections?
i have to work with a partner and his reasoning is this:
"the higher the atomic number, the greater the density because the atomic number is made up of protons so the more protons there are, the closer the electrons are attracted forming a more denser atom"
whereas my reasoning is this:
if I were to give a relationship between density of an element and atomic number, I'd talk about the density equation D = m/v and talk about how the greater the atomic number is, the more protons you'd have, resulting in a higher atomic mass. then I'd compare each element 1 mol and go from there.
Please tell me is my reasoning not correct? Or perhaps my partner is not correct? or perhaps we are both incorrect?
i think your partner is right as density is directly proportional yo yhe mass,which is given by no. of protons.more the protons more is the nuclear effective charge, which attracts the electorns towards the nucleus and make a denser atom.
My take on this is that both arguments have merit, and to a large degree, will prove to be right, but I think your partner elucidated his/her argument better. Yours is not complete. However, I think neither argument takes into account the crystal structure. It's how those atoms, big or small, are packed together that determines the volume.If you look up the densities you and your friend will see that generally density increases with increasing atomic number. However, Na is 0.97 g/cc while K is 0.86 g/cc.
Be is 1.8, Mg is 1.7, Ca is 1.5 etc.